discovery/multi: move SignAnnouncement to netann

netann/sign.go

@@ -0,0 +1,36 @@
+package netann
+
+import (
+	"fmt"
+
+	"github.com/btcsuite/btcd/btcec"
+	"github.com/lightningnetwork/lnd/lnwallet"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
+// SignAnnouncement signs any type of gossip message that is announced on the
+// network.
+func SignAnnouncement(signer lnwallet.MessageSigner, pubKey *btcec.PublicKey,
+	msg lnwire.Message) (*btcec.Signature, error) {
+
+	var (
+		data []byte
+		err  error
+	)
+
+	switch m := msg.(type) {
+	case *lnwire.ChannelAnnouncement:
+		data, err = m.DataToSign()
+	case *lnwire.ChannelUpdate:
+		data, err = m.DataToSign()
+	case *lnwire.NodeAnnouncement:
+		data, err = m.DataToSign()
+	default:
+		return nil, fmt.Errorf("can't sign %T message", m)
+	}
+	if err != nil {
+		return nil, fmt.Errorf("unable to get data to sign: %v", err)
+	}
+
+	return signer.SignMessage(pubKey, data)
+}